FuriousFanBoys interviews Ben Goertzel regarding Artificial Intelligence. Ben started the OpenCog project (an open sourced AI non-profit), acts as an adviser to the Singularity University, and currently bounces back between Hong Kong and Maryland building in-game AI.

Don't attach undue importance to that basic neurological mechanism, primate defence mechanism, a way of forming social bonds in social animal, ...
Now you settle for humour, half a century ago people were going the same way about chess (plus it seems a bit like saying "you can't really be a good mental computer (human one) without having an MMU, antivirus and without ethernet plugs, stack, and so on" - or that a submarine is a very poor ship because it rarely stays on the surface)

How often would they even need humour? What good would it be for them, in majority of the cases? (do you want an autonomous car or aircraft with humour?)

Anyway, there's already some software decent at recognising or creating humour. Also while machines can detect various linguistic nuances (Watson)...

...and while humans can hardly agree on what is humorous, have very different expectations and often can even hardly detect humour from different cultures.

Plus, how much of a virtue it is? We're often mean in our humour - often "guided" by things coming from cognitive biases ...go through their list, really, that is our primary mode of operation.